The present invention relates to chemical compounds and pharmaceutical compositions useful as cognition activators. More particularly, this invention concerns N-[1-oxo-3-(5-oxo-2-pyrrolidinyl)propyl]-alpha-aminoacids, their salts, esters, and amides, pharmaceutical compositions employing such compounds, and a method of treating senility or reversing amnesia in mammals caused by electroconvulsive shock by employing such pharmaceutical compositions.
5-Oxo-2-pyrrolidinepropanoic acid amide, then known as pyrrolidin-2-one-5-propanoic acid amide, was synthesized as a solid derivative in the characterization of gamma-chloropimelic acid dimethyl ester as reported by H. Leuchs and W. Nagel, Chem. Ber., 55B, 3950-3960 (1922). The propanoic acid amide was also obtained by hydrogenation of an ammonia derivative of gamma-ketopimelic acid diethyl ester by A. Scipioni, Ann Chim. (Rome), 42, 53-61 (1952). The propanoic acid amide is also mentioned in Italian Pat. No. 482,946 as an intermediate in the synthesis of gamma-aminopimelic acid.
The piperidide of 5-oxo-2-pyrrolidinepropanoic acid is reported by F. Michael and H. Albers, Ann., 581, 225-237 (1953) as a crystalline derivative from 3,5-dioxopyrrolizidine.